ALVEOLAR (CONSOLIDATION)
• Resultsfrom pathologic process that fills the alveoli with fluid, pus, blood, cells (including tumor
cells) or other substances.
• General features on chest x-ray show ill-defined, fluffy, cottonwool-like appearance of
airspace opacification causing obscuration of pulmonary vessels and air bronchograms.
6.
• Air bronchogram
air-filledbronchi (dark)
being made visible by the
opacification of surrounding
alveoli (grey/white).
9.
LOBAR CONSOLIDATION
• Resultsfrom disease that starts in the
periphery and spreads from one
alveolus to another through the pores
of Kohn.
• At the borders of the disease some
alveoli will be involved, while others
are not, creating ill-defined borders.
• As the disease reaches a fissure, this
will result in a sharp delineation, since
consolidation will not cross a fissure
(limited by visceral pleura).
11.
BULGING FISSURE SIGN
•Refers to lobar consolidation where
the affected portion of the lung is
expanded causing displacement of
the adjacent fissure.
• Classically, it has been described
in right upper lobe
(RUL) consolidation secondary
to Klebsiella pneumonia.
• Other causes include:
• Infective (Strep. pneumoniae,
Pseudomonas aeruginosa, Staph.
aureus)
• Lung adenocarcinoma
• Lung abscess
• Pulmonary haemorrhage
BATWING CONSOLIDATION
• Bilateralperihilar distribution of
consolidation.
• The sparing of the periphery of
the lung is attributed to a better
lymphatic drainage in this area.
• Most typical of pulmonary
oedema, both cardiogenic and
non-cardiogenic.
• Sometimes it is seen in
pneumonias.
14.
ATELECTASIS (COLLAPSE)
• Resultof loss of air in a lung or part of the lung with subsequent volume loss
due to airway obstruction or compression of the lung by pleural fluid or a
pneumothorax.
• General features on chest x-ray:
• Sharply-defined opacity obscuring vessels without air-bronchogram.
• Volume loss resulting in displacement of diaphragm, fissures, hila or
mediastinum.
Passive
Loss of intrapleural
negative pressure
causing lung to be no
longer held against
chest wall.
Obstructive
Occurs as a result of
complete obstruction
of an airway.
No new air can enter,
any air that is already
there is eventually
absorbed into the
pulmonary capillary
system.
15.
Compressive atelectasis
• occursas a result of any thoracic
space-occupying lesion compressing
the lung and forcing air out of the
alveoli
Cicatrization atelectasis
• occurs as a result of scarring or
fibrosis that reduces lung expansion
• common aetiologies
include granulomatous
disease, necrotizing
pneumonia and radiation fibrosis
16.
Right upper lobecollapse
• increased density in the upper
medial aspect of the right
hemithorax
• elevation and/or superior bowing
of the horizontal fissure
• loss of the normal right medial
cardio-mediastinal contour
• elevation of the right hilum
• rotation of the bronchus
intermedius laterally, appearing
more horizontal than usual
• hyperinflation of the right middle
and lower lobe result in increased
translucency of the mid and lower
parts of the right lung
• right juxtaphrenic peak (Kattan sign)
17.
GOLDEN S SIGN
•Typically seen with right upper lobe
collapse.
• Created by a central mass
obstructing the upper lobe bronchus
and should raise suspicion of a
primary bronchogenic carcinoma.
• Can also be caused by other central
masses, such as metastasis, primary
mediastinal tumour, or enlarged
lymph nodes.
18.
Right middle lobecollapse
• right mid to lower zone air
space opacification (which can
be subtle)
• the normal horizontal fissure is
no longer visible (as it rotates
inferiorly rendering it non-
tangential to the x-ray beam)
• obscuration of the right heart
border
• lateral projection: a triangular
opacity in the anterior aspect
of the chest overlying the
cardiac shadow.
19.
Right lower lobecollapse
• triangular opacity at the right lower
zone (usually medially) with the
apex pointing towards the right
hilum
• obscuration of the medial aspect of
the dome of right hemidiaphragm
• inferior displacement of the right
hilum
• descending interlobar pulmonary
artery is not visible
• preservation of a clear right heart
border, which is contacted by the
right middle lobe
• inferior displacement of
the horizontal fissure
20.
Left upper lobecollapse
• Collapsed left upper lobe appears as a
hazy or veiling opacity extending out from
the left hilum and fading out inferiorly
• Obscuration of parts of the normal
cardiomediastinal contour particularly
where the lingular segments abuts the left
heart border
• Luftsichel sign the hyperexpanded superior
segment of the left lower lobe insinuates
between the left upper lobe and the
superior mediastinum, sharply silhouetting
the aortic arch resulting in a sickle-shaped
lucency medially
• The left hilum is drawn upwards
21.
Left lower lobecollapse
• triangular left lower zone opacification
(usually medially, retrocardiac) with the
apex pointing towards the left hilum
• edge of the collapsed lung may create a
'double cardiac contour'
• inferior displacement of the left hilum
• Flat waist sign: flattening of the left heart
border
• obscuration of the left hemidiaphragm
• obscuration of the descending aorta
• preservation of a clear left heart border,
which is contacted by the lingular segments
of the left upper lobe
• inferior displacement of the oblique fissure
• descending interlobar pulmonary artery is
not visible
22.
Plate atelectasis
• Focalarea of subsegmental
atelectasis that has a linear shape.
• May appear to be horizontal, oblique
or perpendicular line of 1-3 mm in
thickness.
• Frequently seen in patients in ICU due
to poor ventilation and postoperative
patients.
• In most cases these findings have no
clinical significance and are seen in
smokers and elderly.
23.
SILHOUETTE SIGN
• Pathologicalloss of two adjacent
structures differentiation (i.e. lung
and mediastinal border).
• It denotes that a mediastinal
border can only be obscured by
pathology which is in direct
anatomical contact.
• Useful in localising areas of
airspace opacities, atelectasis or
mass within the lung.
Loss of silhouette:
• right paratracheal stripe: right upper
lobe
• right heart border: right middle lobe
or medial right lower lobe
• right hemidiaphragm: right lower
lobe
• aortic knuckle: left upper lobe
• left heart border: lingular segments
of the left upper lobe
• left hemidiaphragm or descending
aorta: left lower lobe
24.
INTERSTITIAL OPACITY
• Reticularopacities or small nodules due
to involvement of the supporting tissue
of the lung parenchyma (interstitium).
• Results from thickening of any of the
interstitial compartments by blood,
water, tumor, cells, fibrous disease or
any combination thereof.
• Can be reticular, reticulonodular, or
linear where the predominant pattern
is a result of the underlying
pathological process.
25.
Reticular interstitial opacity
•Complex network of
curvilinear opacities that
usually involved the lung
diffusely.
• Can be subdivided by their
size based on the size of the
lucent spaces created by the
intersection of lines.
26.
• Fine "ground-glass"(1-2 mm):
seen in processes that thicken
the pulmonary interstitium to
produce a fine network of lines,
e.g. interstitial pulmonary oedema
• Medium "honeycombing" (3-10
mm): commonly seen in pulmonary
fibrosis with involvement of the
parenchymal and peripheral
interstitium
• Coarse (>10 mm): cystic spaces
caused by parenchymal destruction,
e.g. usual interstitial pneumonia,
pulmonary sarcoidosis, pulmonary
Langerhans cell histiocytosis.
28.
Reticulonodular interstitial opacity
•Overlap of reticular shadows or by the
presence of reticular shadowing
and pulmonary nodules.
• Relatively common appearance on
a chest radiograph, very few diseases
are confirmed to show this pattern
pathologically:
silicosis
pulmonary sarcoidosis
berylliosis
lymphangitic carcinomatosis
hepatopulmonary syndrome -
basal
pneumocystis pneumonia
bronchocentric granulomatosis
pulmonary Langerhans cell
histiocystosis
lymphocytic interstitial pneumonitis
Erdheim-Chester disease
29.
Linear interstitial opacity
•Seen in processes that thicken the axial (bronchovascular) interstitium or the
peripheral pulmonary interstitium.
• Axial: diffuse thickening along the bronchovascular tree seen as parallel opacities
radiating from the hila (seen transversely) or peribronchial cuffing (seen en face).
• Peripheral: thickening of the peripheral interstitium (either medially or laterally)
produces Kerley lines.
• Axial interstitial thickening is difficult to distinguish from airways disease that result
in bronchial wall thickening, (e.g. bronchiectasis, asthma) and most often seen
in interstitial pulmonary oedema.
30.
Kerley lines (septallines)
• Prominent interlobular
septa in the pulmonary
interstitium because of
lymphatic engorgement or
oedema of the connective
tissues of the interlobular
septa.
• Usually occur when
pulmonary capillary wedge
pressure reaches 20-25
mmHg.
Causes
• pulmonary oedema
• neoplasm
• lymphangitic spread of cancer
• breast cancer
• colon cancer
• stomach cancer
• pancreatic cancer
• lung cancer
• lymphoma
• pulmonary lymphoma
• pneumonia
• viral pneumonia
• mycoplasma pneumonia
• Pneumocystis pneumonia
• interstitial pulmonary fibrosis
• pneumoconiosis
• sarcoidosis
31.
Kerley A
• 2-6cm long oblique lines that
are <1 mm thick and course
towards the hila.
• Represents thickening of the
interlobular septa that contain
lymphatic connections between
the perivenous and
bronchoarterial lymphatics deep
within the lung parenchyma.
• On chest radiographs they are
seen to cross normal vascular
markings and extend radially
from the hilum to the upper lobes.
32.
Kerley B
• Thinlines 1-2 cm in length in
the periphery of the lung(s).
• Represent thickened subpleural
interlobular septa and are
usually seen at the lung bases.
• Perpendicular to the pleural
surface and extend out to it.
*Kerley D lines are exactly the
same as Kerley B lines, except that
they are seen on lateral chest
radiographs in the retrosternal air
gap.
33.
Kerley C
• shortlines which do not
reach the pleura and do not
course radially away from
the hila (neither A nor B).
34.
NODULES OR MASSES
Suggestedrisk factors to consider
include older age, heavy smoking,
irregular or spiculated margins, and
upper lobe location.
• A discrete, well-
marginated, rounded
opacity less than or equal
to 3 cm in diameter.
• Lesions smaller than 3 cm
are most commonly benign
granulomas, while lesions
larger than 3 cm are
treated as malignancies
until proven otherwise and
are called masses.
35.
Metastases
• Typically appearas
peripheral, rounded nodules
of variable size, scattered
throughout both lungs
predominantly lower lobes
and subpleural.
36.
Mucoid impaction
• Canmimic the appearance of
lung nodules or a mass.
• Commonly seen in patients
with bronchiectasis, as in cystic
fibrosis (CF), allergic
bronchopulmonary
aspergillosis (ABPA) and
bronchial atresia.
• ‘Finger-in-glove’ appearance:
mucus in dilated bronchi looks
like fingers in glove.
Monod sign
• Gasthat surrounds a
mycetoma (most commonly
an aspergilloma) in a pre-
existing pulmonary cavity.
• Gas around the mycetoma is
often crescent-shaped and
hence, the term air crescent
sign is used interchangeably.
41.
Pneumatocele
• Majority ofpneumatoceles occur
as a result of pneumonia, most
common causative agents being S.
aureus.
42.
Bulla
• Focal regionsof emphysema with
no discernible wall which measure
more than 1 or 2 cm in diameter.
• Often subpleural in location and
are typically larger in the apices
43.
Emphysema
• Abnormal permanentenlargement
of the airspaces distal to the
terminal bronchioles accompanied
by destruction of the alveolar wall
and without obvious fibrosis.
• Chest x-ray does not image
emphysema directly, but indirect
signs
• hyperinflation
• paucity of blood vessels
• pulmonary arterial hypertension
features (pruning of peripheral
vessels, increased calibre of
central arteries, right ventricular
enlargement)
44.
MEDIASTINUM
Mediastinal division
• Superior:Above a line drawn from
lower border of T4 to sternal angle.
• Anterior: Between anterior part of
the pericardium and posterior to the
sternum.
• Middle: Occupied by heart and its
vessels .
• Posterior: Between posterior part of
the heart and thoracic spine, extends
down behind posterior part of
diaphragm as it descends down.
45.
Mediastinal mass
• Amediastinal mass does not
contain air bronchograms.
• The margins with the lung will
be obtuse.
• Disruption of mediastinal lines
(azygoesophageal recess,
anterior and posterior junction
lines).
• There can be associated spinal,
costal or sternal abnormalities.
HILUM OVERLAY SIGN
•To differentiate whether a hilar opacity
on a frontal chest radiograph is located
within the hilum or anterior/posterior to
it.
• Loss of normal pulmonary vessels
(interlobar artery, upper lobe arteries,
and left lower lobar artery) silhouette –
lesion from hilum. Causes of these
opacities include middle mediastinal
tumours, hilar adenopathy, pericardial
effusion, vascular enlargement,
and cardiac enlargement.
• Preserved hilar vessels implies the
cause of the opacity is not in contact
with the hilum and is, therefore, either
anterior or posterior to it. Most of these
opacities are masses in the anterior
mediastinum.
48.
CERVICOTHORACIC SIGN
• Variationof the silhouette sign on
frontal chest radiography used to
determine whether a superior
(para)mediastinal soft tissue mass is
anterior or posterior to the trachea.
• As the anterior mediastinum ends at
the level of the clavicles, the upper
border of an anterior mediastinal
lesion cannot be visualised
extending above the clavicles. –
Positive cervicothoracic sign.
• Any lesions with a discernible upper
border above clavicular level must
be located posteriorly in the chest
(posterior mediastinum). – Negative
cervicothoracic sign.
49.
PLEURA
• Serous membranecomposed of
mesothelial cells and loose
connective tissue.
• Divided into parietal pleura and
visceral pleura.
• Contains up to 5 ml of fluid within
the two layers and normally not
separated.
• No communication between the
right and left pleural cavities.
50.
Pleural opacities
• Themost common condition is pleural
thickening.
• Differentiation between pulmonary and
extrapleural lesion is crucial in making
appropriate diagnosis.
Pulmonary lesion usually have acute
angles with the chest wall, are centered in
the lung, and engulf the pulmonary
vasculature.
A pleural opacity shows obtuse angles
with the lateral chest wall with tapered
margins, displaces the pulmonary
vasculature, changes its location on
respiration, and may show incomplete
border sign on chest radiograph
Extrapleural lesions may arise from
extrapleural fat, ribs, intercostal muscles,
and neurovascular bundle; cause erosion
of ribs.
53.
Pleural effusion
• Presenceof fluid in
the pleural space.
• It takes about 200-300 ml of
fluid before it comes visible on
an CXR. About 5 litres of pleural
fluid are present when there is
total opacification of the
hemithorax.
Transudate Exudate
Increased in hydrostatic pressure/
decreased capillary oncotic
pressure.
Seen in cases e.g.:
• cardia failure
• nephrotic syndrome
• cirrhosis
• trauma
• asbestos exposure
• post coronary artery bypass
grafting: small unilateral left-
sided pleural effusion can be
common
• certain medications: dasatinib
Increased in permeability of the
microcirculation or alteration in the
pleural space drainage to lymph
nodes.
Seen in cases e.g.:
• bronchial carcinoma
• secondary (metastatic)
malignancy
• pulmonary
embolism and infarction
• pneumonia
• tuberculosis
• mesothelioma
• rheumatoid arthritis
• systemic lupus erythematosus
(SLE)
• lymphoma
54.
• Features onplain radiograph (erect)
blunting of the costophrenic angle
blunting of the cardiophrenic angle
fluid within the horizontal or
oblique fissures
eventually, a meniscus will be seen,
laterally and gently sloping
medially (however not visible in
case of hydropneumothorax )
with large volume effusions,
mediastinal shift occurs away from
the effusion (however, if coexistent
collapse dominates then
mediastinal shift may occur towards
the effusion)
55.
• Features onplain radiograph
(supine)
• no meniscus, and only a veil-like
increased density of the hemithorax
may be visible as the fluid collects
posteriorly
56.
SUBPULMONIC EFFUSION
• Pleuraleffusion that collects
between the lung base and
diaphragm.
• Can only be seen on erect
radiograph:
• apparent elevation and
flattening of the diaphragm
(what appears to be the
diaphragm actually represents
the visceral pleura, and the true
diaphragm is obscured by the
presence of infrapulmonary fluid)
• peak of pseudodiaphragm lies
lateral to the normal position
• increased distance between the
pseudodiaphragm and the
gastric bubble (on the left).
57.
Pleural plaques
• Theyhave irregular shapes with
thickened nodular edge (holly leaf
appearance) and do not look like
a lung masses or consolidations.
• Bilateral and extensive in asbestos
related pleural plaques.
• Unilateral, calcified pleural
plaques seen in
• infection (TB)
• empyema
• hemorrhagic
58.
Pneumothorax
• Presence ofair in
the pleural space.
• Can be
• primary spontaneous: no
underlying lung disease
• secondary spontaneous:
underlying lung disease is
present
• iatrogenic/traumatic
Primary spontaneous Secondary spontaneous
Tall and thin people are more likely to
develop
There are well–known associations
• Marfan syndrome
• Ehlers-Danlos syndrome
• alpha-1-antitrypsin deficiency
• homocystinuria
Cystic lung disease
• bullae, blebs
• emphysema, asthma
• pneumocystis jiroveci pneumonia (PJP)
• honeycombing: end-stage interstitial
lung disease
• lymphangiomyomatosis (LAM)
• Langerhans cell histiocytosis (LCH)
• cystic fibrosis
Parenchymal necrosis
• lung abscess, necrotic
pneumonia, septic emboli, fungal
disease, tuberculosis
• cavitating neoplasm, metastatic
osteogenic sarcoma
• radiation necrosis
• pulmonary infarction
other
• catamenial pneumothorax: recurrent
spontaneous pneumothorax during
menstruation, associated
with endometriosis of pleura
• rarely pleuroparenchymal
fibroelastosis
Iatrogenic/traumatic
Iatrogenic:
• percutaneous biopsy
• barotrauma (e.g., divers), ventilator
• radiofrequency (RF) ablation of
lung mass
• endoscopic perforation of the
oesophagus
• central venous catheter insertion,
nasogastric tube placement
Trauma:
• pulmonary laceration (rib fracture)
• tracheobronchial rupture
• acupuncture 14,15
• oesophageal rupture
59.
• On plainradiograph (erect) it
demonstrates
• visible visceral pleural edge is seen
as a very thin, sharp white line
• no lung markings are seen
peripheral to this line
• peripheral space is radiolucent
compared to the adjacent lung
• lung may completely collapse
• subcutaneous emphysema and
pneumomediastinum may also be
present
60.
• Supine projectionmay only detect 50%
of the pneumothoraces. Signs include:
• relative lucency of the involved
hemithorax
• deep, sometimes tongue-like,
costophrenic sulcus: deep sulcus sign
• increased sharpness of the adjacent
mediastinal margin and diaphragm
• increased sharpness of the cardiac
borders or diaphragm
• visualisation of the anterior costophrenic
sulcus: double diaphragm sign
• visualisation of the inferior edge of the
collapsed lung above the diaphragm
• depression of the ipsilateral
hemidiaphragm
• Shift of mediastinum away from the
pneumothorax indicates tension
pneumothorax.
Editor's Notes
#10 The most common cause for lobar consolidation is pneumonia.
#16 Kattan sign-peaked or tented appearance of a hemidiaphragm which can occur in the setting of lobar collapse or post lobectomy (lung). It is caused by retraction of the lower end of diaphragm at an inferior accessory fissure (most common 1), major fissure or inferior pulmonary ligament. It is commonly seen in collapse of the left or right upper lobes but may also be seen in middle lobe collapse.